The commission shall have absolute control and supervision over the employment, promotion, discharge, and suspension of all officers and employees of the fire department of such city and these powers shall extend to and include the chief and assistant chief of such, and all inspectors, fire wardens, electricians, engineers, auto mechanics, clerks, and other persons engaged in the fire prevention and protection service in the city. The commission may not, however, prescribe any residency requirements for the positions under its control, unless approved by the city council.
The commission shall immediately after its appointment and organization grade and classify all of these employees of the fire department of the city and a service register shall be prepared for the purpose, in which shall be entered, in their classes, the names, ages, compensation, period of past employment, and such other facts and data with reference to each employee as the commission may deem useful.
The commission shall keep a second register to be known as the application register in which shall be entered the names and addresses in the order of the date of application of all applicants for examination and the offices or employments they seek. All applications shall be upon forms prescribed by the commission and contain such data and information as the commission shall deem necessary and useful.